In a mobile cellular communications system power control and space-time diversity are applied in combination to the uplink and downlink. In the uplink, mobile powers and equalization/diversity combining vectors at base stations are, calculated jointly, with the result that the mobile transmitted power is minimized, while the Signal to Noise Ratio (SNR) at each link is maintained above a threshold. In the downlink, a multitap transmit diversity strategy adjusts the transmit weight vectors with the result that the SNR at each mobile is set to a specified value. The combination of power control and space-time diversity apply to networks with fading channels, including networks in which the number of cochannels and multipaths are larger than the number of antenna elements. The invention achieves the optimal solution for the uplink that minimizes the mobile power, and achieves a feasible solution for the downlink if there exists any.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for adaptive receiver beamforming and transmitter power control in a cellular radio network having communications links between base stations and mobile stations, the network employing base station receiver diversity and mobile station power control, the method comprising the following steps: determining a refined base station receive diversity weight vector for which a first quality measure is highest; and using the refined base station receive diversity weight vector to determine a refined set of mobile transmitter powers for which a second quality measure is highest.
2. The method of claim 1 wherein the first quality measure is the minimum value in the set of base station receiver signal to noise ratios.
3. The method of claim 1 wherein the second quality measure is the reciprocal of the sum of the mobile station transmitter powers.
4. The method of claim 1 wherein the receive signals at the base stations are oversampled.
5. A method for adaptive receiver beamforming and transmitter power control in a cellular radio network having communications links between base stations and mobile stations, the network employing base station receiver diversity and mobile station power control, the method comprising the steps of: determining a refined base station receive diversity weight vector for which a first quality measure is highest; and using the refined base station receive diversity weight vector to determine a refined set of mobile transmitter powers for which a second quality measure is highest, such that total power transmission is minimized while maintaining a selected minimum transmission quality.
6. The method of claim 5 wherein the total transmitted power is defined as: min i P i A P S , T , i .
7. The method according to claim 5 including determining the joint power and control and combining vector.
8. The method according to claim 5 including performing optimal power control over the network based upon local information.
9. A method for adaptive transmitter beamforming and power control in a cellular radio network having communications links between base stations and mobile stations, the network employing transmitter diversity and power control in the base stations, the method comprising the step of jointly determining a refined base station transmit diversity weight vector and a refined set of base station transmitter powers, for which a quality measure is satisfied.
10. The method of claim 9 wherein the quality measure is a set of predetermined values of the mobile receiver signal to noise ratios.
11. The method of claim 9 wherein the receive signals at the base stations are oversampled.
12. The method of claim 5 , further comprising providing the one of the base stations with a channel response feedback pertaining to a respective one of the mobile stations for optimizing the respective one of the links therebetween.
13. The method of claim 5 , further comprising providing the one of the base stations with interference feedback pertaining to a respective one of the mobile stations for optimizing the respective one of the links therebetween.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
November 20, 1998
April 23, 2002
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.